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It was from Assyria, known as Mesopotamia (between the Tigris and Euphrates) that the first civilization began, and gave rise to an intellectual thought process that helped build scientific as well as religious basis for all other cultures.

A Population Genetics Study in the Assyrian Population of the United States (Nineveh, Volume 35, Number 2)

By: PhD Candidate Rebecca Arjovik RayPublish Date: 9/8/2011

This article is a population genetics study which included samples from 206 random, unrelated Assyrian volunteers. In this study, allele frequencies for the 9 ABI Profiler Plus™ CODIS STR human DNA identification loci (D8S1179, D21S11, D7S820, D3S1358, D18S51, D5S818, and FGA) were determined in the Assyrian population of the United States. Each saliva sample was genotyped and 199 of the 206 collected samples provided a full genetic profile. Allele frequencies were determined by the gene count method. After statistical analysis, the population adhered to Hardy-Weinberg Equilibrium. This study concludes that the U.S. Assyrian Profiler Plus™ loci allele frequency database generated by this study should be used in lieu of the U.S. Caucasian Profiler Plus™ loci allele frequency database in the performance of human identification testing among U.S. Assyrians. Given the results of this study, if an Assyrian is accused of a crime or of the paternity of a child, the inclusion number of his profile should be calculated using the Assyrian population database allele frequencies, not those for U.S. Caucasians (which is the database that would have been used by default prior to this study).

ALLELE FREQUENCIES OF 9 STR CODIS LOCI IN THE ASSYRIAN POPULATION OF THE UNITED STATES.

The Importance of Population Studies

The frequency of any given STR profile in a population is calculated on the basis of Hardy-Weinberg Equilibrium (HWE) population genetics equations that relate allele frequencies to genotype frequencies in populations. Therefore, to calculate the probability that a particular STR genotype might occur at random in a population (i.e. to assign an inclusion number to a “match”), data must be gathered from that population to make an estimate of the frequency of each allele. An allele frequency study typically requires that 100-200 individuals from the target population be genotyped.

Obviously, since HWE statistics are also used, validating the database also requires tests for (HWE) at all loci under consideration, to ensure that genotype frequencies can be accurately calculated from allele frequencies. For example, in the U.S. there are at least five genetically distinct sub-populations with respect to the Profiler Plus™ loci: African-Americans, Caucasians, Hispanics, Asians, and Native Americans, and the allele frequencies for all of these loci have been determined with precision in these groups.

Moreover, the distribution of alleles at these loci have been tested for HWE for all these subpopulations and HWE has been confirmed, allowing HWE equations to be used to calculate the frequency of any particular profile from the allele frequencies. Numerous new STR population databases are published every year by the Journal of Forensic Sciences and Forensic Sciences International, and all these new databases face the same challenge of validation by testing the allelic distributions at each locus under study for conformance to HWE.

There are still some ethnic sub-populations in the United States that are likely to be genetically distinct at the CODIS loci, but for whom there is no STR allele frequency database. One example is the Assyrians, who have been reproductively isolated from other groups, due to their unique religious and cultural beliefs, for hundreds of years.

It is interesting to note that in a study conducted at the University of California’s School of Medicine in San Francisco, Dr. Elias found that Assyrians have a distinct distribution of the ABO blood group alleles, and that it differs from all other groups in the Middle East. In fact, Assyrians from the two regions in Iran, Tehran, and especially Urmia, were found to have high levels of homozygosity for ABO alleles, suggesting that there has been a lack of intercultural mixing that can still be detected at the genetic level today.

In this study, allele frequencies for the 9 ABI Profiler Plus™ CODIS STR human DNA identification loci (D8S1179, D21S11, D7S820, D3S1358, D18S51, D5S818, and FGA) were determined in the Assyrian population of the United States. Saliva samples were collected from 206 U.S. Assyrian volunteers who were not closely related and who were representative of the U.S, Assyrian population.

Distribution of the alleles at 8 of the 9 loci (D8S1179, p=0.88; D21S11, p=0.37; D7S820, p=0.72; D3S1358, p=0.078; D5S818, p=0.7936; FGA, p=0.12) were found to conform to HWE expectations. However, the distribution of alleles at D18S51 showed an unexpectedly high level of homozygosity (p = 0.0039; expected homozygosity = 0.12 , observed homozygosity = 0.19), and even applying a Bonferroni Correction (which would adjust p from 0.05 to 0.005 for each locus across a nine locus data set) still did not bring the D18S51 allelic distribution within the required range. Assyrians was then compared to that of U.S. Caucasians using Chi-Square analysis (p = 0.05), and the distribution was found to be significantly different from that of the U.S. Caucasian database at 5 (D3S1358, p=0.0377; D8S1179, p=0.0004; D21S11, p=0.0221; D13S317, p=0.0455; D7S820, p=0.0026) of the 9 loci.

Thus, this study concludes that the U.S. Assyrian Profiler Plus™ loci allele frequency database generated by this study should be used in lieu of the U.S. Caucasian Profiler Plus™ loci allele frequency database in the performance of human identification testing among U.S. Assyrians. However, the study also cautions that there is an anomaly at the D18S51 locus among U.S. Assyrians that requires further study before this locus can be included in statistical calculations of genotype frequencies generated from the database. Given the results of this study, if an Assyrian is accused of a crime or of the paternity of a child, the inclusion number of his profile should be calculated using the Assyrian population database allele frequencies, not those for U.S. Caucasians (which is the database that would have been used by default prior to this study).